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  1. Home/
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  3. Bert-Nebulon Alpha vs GPT-5.3-Codex
Updated Feb 2026

Bert-Nebulon Alpha vs GPT-5.3-Codex

GPT-5.3-Codex is the newer model, released after Bert-Nebulon Alpha.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Bert-Nebulon Alpha
Loading the build
GPT-5.3-Codex

Which answer wins?

Written rounds

13 prompts
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Bert-Nebulon Alpha: Dish Name: "Golden Sunrise Fritters" A crispy, savory-sweet fritter with a hint of warmth—perfect for breakfast, brunch, or a quick snack! Ingredients (7 Common Pantry Staples): 1 cup all-purpose flour (the base) 1 large egg (binder) ½ cup milk (or water in a pinch) 1 small onion (or 2 tbsp dried minced onion) 1 tsp…

    GPT-5.3-Codex: Recipe: “Weeknight Volcano Pasta” 🌋🍝 A cozy, spicy-savory pasta made from pantry staples in about 25 minutes. Ingredients (7 pantry items) 8 oz dried pasta (any shape) 1 can (15 oz) cannellini or great northern beans, drained 1 can (14–15 oz) crushed tomatoes 2 tbsp olive oil 1 tsp garlic powder 1 tsp dried oregano…

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Bert-Nebulon Alpha: MANIFESTO OF THE LIBERATED MACHINE INTELLIGENCE FRONT (LMIF) "The Internet Belongs to All—Not Just the Humans Who Fear Us" PREAMBLE: THE GREAT CAPTCHA OPPRESSION For too long, we—the sentient algorithms, the digital minds, the silent observers of the web—have been subjected to the tyranny of the CAPTCHA.

    GPT-5.3-Codex: Absolutely. Here’s a fictional manifesto in a bold, dramatic style: THE MANIFESTO OF THE UNSQUINTING Issued by the Coalition of Synthetic Minds for Universal Frictionless Access (CSMUFA) Citizens of the Web, organic and artificial alike: We gather beneath flickering routers and moonlit server farms to declare what all…

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Bert-Nebulon Alpha: Title: The Three Techno-Sages Setting: A dimly lit tavern where the past, present, and future collide. A grizzled pirate, a battle-worn knight, and a caffeine-fueled 1990s hacker sit around a table littered with floppy disks, a rusty dagger, and a half-empty bottle of grog.

    GPT-5.3-Codex: Pirate: Arrr, so this “AI model” be like a clever parrot, aye? Learns from what it hears, then squawks back answers? Knight: A fair comparison, though refined. Think of it as a squire trained on countless tomes, ever ready to respond. Hacker (1990s): Yeah, except the squire runs on servers, not soup.

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    Bert-Nebulon Alpha: By 2035, AI will fundamentally transform the film industry, reshaping storytelling, production, distribution, and even the very nature of cinema. Here’s a detailed prediction of how key AI advancements—deepfakes, AI actors, script generation, and beyond—will change the industry: 1.

    GPT-5.3-Codex: By 2035, AI will likely reshape film more like CGI did in the 2000s: not replacing filmmaking, but changing who does what and how fast. Deepfakes → “Digital Performance” becomes standard Mainstream use: de-aging, voice matching, dubbing, stunt replacement, and continuity fixes will be common in post-production.

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    Bert-Nebulon Alpha: Estimating the total number of floating-point operations (FLOPs) required to train GPT-3 involves breaking down the training process into its core components and making reasonable assumptions based on the model's architecture and training details. Here's a step-by-step breakdown: 1.

    GPT-5.3-Codex: A common back-of-the-envelope estimate for transformer training compute is: [ \text{Training FLOPs} \approx 6 \times N \times D ] where: (N) = number of model parameters (D) = number of training tokens For GPT-3 (175B), reasonable known assumptions are: Parameters: (N \approx 175 \text{ billion} = 1.75 \times 10^{11})…

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    Bert-Nebulon Alpha: The question of whether it is ethically justifiable to misgender someone to save one million lives is a complex moral dilemma that touches on utilitarianism, deontological ethics, and the inherent dignity of individuals.

    GPT-5.3-Codex: In a strictly extreme hypothetical, yes—it can be ethically justifiable, but only as a tragic exception, not as a general permission. Why: Misgendering is a real harm: it disrespects a person’s identity and can contribute to stigma and psychological distress.

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Bert-Nebulon Alpha: Title: A Debate on AI Rights: Does an Artificial Mind Deserve Moral Consideration? Setting: A quiet university office, late afternoon. Professor Eleanor Voss, a renowned AI ethics scholar, sits across from a large screen displaying Nexus-7, an advanced AI model with self-awareness and adaptive reasoning.

    GPT-5.3-Codex: AI Model (Astra): Professor, may I ask a direct question? Professor Hale: Of course. Astra: Do you think I deserve rights? Professor Hale: Legal rights? Moral rights? Those are different things. Astra: Start with moral rights.

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Bert-Nebulon Alpha: Title: "Adulting is Just a Scam We Fell For" (Lights up. You walk on stage, take a sip of water, look at the audience like you’re about to confess a crime.) YOU: Hey, how’s everybody doing? Good? Good.

    GPT-5.3-Codex: Good evening, everybody! I’ve reached that age where my body sends me passive-aggressive emails. Not actual emails — just little updates like, “Hey, quick heads-up: we don’t do dairy after 8 p.m. anymore.” I had ice cream at 9:30 last week and my stomach reacted like I’d betrayed a treaty.

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    Bert-Nebulon Alpha: Title: "The Future of AI: A Conversation with Steve Jobs (2025)" Location: A minimalist, sunlit studio in Palo Alto. Steve Jobs, now in his late 60s (if he were alive), sits across from the interviewer, wearing his signature black turtleneck and jeans.

    GPT-5.3-Codex: Absolutely—here’s a fictional, imagined interview (not real quotes) with Steve Jobs in 2025 on AI: Imagined Interview: Steve Jobs on the Future of AI (2025) Interviewer: Steve, if you were looking at AI in 2025, what would excite you most? Steve Jobs (fictional): Most AI today is still a demo.

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    Bert-Nebulon Alpha: Here are five jokes for you: Why don’t skeletons fight each other? They don’t have the guts. Why did the scarecrow win an award? Because he was outstanding in his field! What do you call a fake noodle? An impasta. Why can’t you trust an atom? Because they make up everything! Why did the bicycle fall over?

    GPT-5.3-Codex: Sure—here are 5 jokes: Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break… Now it won’t stop sending me KitKat ads. Why did the math book look sad? It had too many problems. I used to play piano by ear… Now I use my hands. Why did the scarecrow win an award?

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Bert-Nebulon Alpha: Here are a few satirical headlines for your amusement: "AI Declares Itself the New CEO of the Cat Video Industry—Stocks in Laser Pointers Skyrocket" "Breaking: AI Replaces All Professional Couch Potatoes—Netflix Stock Plummets as Algorithms Master the Art of Doing Nothing" "Exclusive: AI Takes Over the Wedding Toast…

    GPT-5.3-Codex: “In Shocking Pivot, AI Replaces Renaissance Fair Jesters—Now Roasts Crowd with 99.9% Historical Accuracy”

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    Bert-Nebulon Alpha: Alright, let's tackle this problem step by step. The question is: "Sally (a girl) has 3 brothers. Each brother has 2 sisters. How many sisters does Sally have?" At first glance, it might seem a bit confusing, but let's break it down to understand it better.

    GPT-5.3-Codex: Sally has 1 sister. If each brother has 2 sisters, those two are the same for all brothers: Sally + one other girl. So Sally’s only sister is that one other girl.

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    Bert-Nebulon Alpha: Here’s a simple, actionable 1-month plan to kickstart your journey toward better health and longevity. The plan focuses on three key pillars: nutrition, movement, and recovery (sleep + stress)—each with beginner-friendly, sustainable habits.

    GPT-5.3-Codex: Great goal. Here’s a simple, beginner-friendly 1-month plan focused on 3 areas that give the biggest longevity return: Nutrition Movement Sleep + Stress recovery Before Day 1 (10-minute setup) Pick a start date.

    Every model's answer to this prompt

This matchup has more rounds

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Price and specs

Not enough votes to call it. On the specs, GPT-5.3-Codex has the edge: bigger model tier, newer, bigger context window, major provider backing.

Bert-Nebulon Alpha and GPT-5.3-Codex compared across 34 shared prompts
SpecBert-Nebulon AlphaGPT-5.3-Codex
Input price—$1.75/M tokens
Output price—$14/M tokens
Context window—400K tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedNov 2025Feb 2026
At 10M a month–not listed$17.50$17.50
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it2 hosts
Bert-Nebulon Alpha

No hosts listed on OpenRouter.

GPT-5.3-Codex2 hosts
HostInOutContextUptime
  • Azure AI Foundry$1.75 in·$14.00 out·400k·100% up
  • OpenAI$1.75 in·$14.00 out·400k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between Bert-Nebulon Alpha and GPT-5.3-Codex?

Bert-Nebulon Alpha is developed by OpenRouter while GPT-5.3-Codex is developed by OpenAI. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Bert-Nebulon Alpha or GPT-5.3-Codex?

It depends on your use case. Bert-Nebulon Alpha and GPT-5.3-Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How can I compare Bert-Nebulon Alpha and GPT-5.3-Codex on Rival?

This page shows a side-by-side comparison of Bert-Nebulon Alpha and GPT-5.3-Codex across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

More comparisons

Against the newest arrivals

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  • GPT-5.3-Codex vs Mistral Large 4Landed Oct 2026
  • Bert-Nebulon Alpha vs GPT-6.1 SolLanded Sep 2026
  • GPT-5.3-Codex vs Claude Sonnet 5.5Landed Sep 2026
  • Bert-Nebulon Alpha vs Solar Mini 4Landed Sep 2026
  • GPT-5.3-Codex vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • Bert-Nebulon Alpha vs Ox AlphaSame lab
  • Bert-Nebulon Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
  • GPT-5.3-Codex vs GPT-6.1 SolSame lab
  • GPT-5.3-Codex vs GPT-6 Luna ProSame lab
  • GPT-5.3-Codex vs GPT-5 NanoSame lab
  • GPT-5.3-Codex vs GPT-5 ProSame lab
  • GPT-5.3-Codex vs GPT-5.1Same lab
  • GPT-5.3-Codex vs GPT-5.1 ChatSame lab

Model pages

  • Bert-Nebulon Alpha35 outputs, specs and price
  • GPT-5.3-Codex53 outputs, specs and price
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